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    <script>
        // 基本语法
        // const 常量名 = 值;

        // const具备let特点

        // 特点：
        // - 建议常量名大写
        // - 声明了常量必须赋值，不赋值报错
        // - 常量值不能修改

        // const a;  //SyntaxError: Missing initializer in const declaration

        const b = 100;
        console.log(b);

        // b = 222; //TypeError: Assignment to constant variable.

        const PI = Math.PI;
        console.log(PI);


    </script>
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